For all the offseason change that the Celtics endured, from hiring a new coach to overhauling the roster, one aspect of last season’s team almost certainly will be the same when the regular season starts next month.

The Celtics all but officially ruled out the chance that Rondo, who is recovering from knee surgery to repair a torn anterior cruciate ligament, could return for the team’s Oct. 30 regular-season opener in Toronto, with Danny Ainge saying Tuesday he’d be “shocked” if Rondo is healthy enough to play by then.

Ainge, the Celtics president of basketball operations, said a timeline remains unclear for Rondo’s return — it’s week to week, he said — but Ainge did hint in a radio interview that Rondo might not play until December.

“I don’t think we would ever succumb to the pressure of bringing back a player from an ACL too soon,” Ainge said before the Shamrock Foundation’s sixth annual Teeing up For Kids Golf Tournament at Wollaston GC in Milton.

“We’ve got to do what’s right for him. He’s young (27); maybe if he was 37 and it was his last year, but he’s still so young. And he’s our best player. We can’t afford to make any mistakes in judgment on when to bring him back.”

Ainge said he and Celtics coach Brad Stevens have been in “constant contact” with Rondo as the team prepares to open training camp next Tuesday in Newport, R.I. Rondo will be at training camp, watching and helping the younger players while also doing rehab.

“He seems to be in a really good place, emotionally, mentally,” Ainge said, “and now we’re just trying to get the physical part done — and he’s got a ways to go.”

Rondo was diagnosed with a torn ACL Jan. 27 after suffering the injury a few days earlier in a double-overtime loss to Atlanta.

He had surgery in mid-February, performed by Dr. James Andrews, and he has spent the summer rehabbing.

“My understanding, and the last time that we’ve had discussions about it, was that [Rondo’s return is] very indeterminate still,” Stevens said. “But it sounds like that it would be unlikely that he would be playing at the very start of the regular season. What that means beyond that, I think that’s going to be on his doctors, his training staff, him, making the call on when he’s ready.

“I’ve told [Rondo] from Day 1, ‘Come back when you’re ready.’ I think it’s really important that he feels good when he’s back and ready to play.”

Stevens said he wasn’t sure who would fill in for Rondo at point guard in the meantime.

The only name Stevens mentioned was Avery Bradley, who played that position for much of last season after Rondo suffered his injury.

“I don’t know exactly how we’ll progress from here as far as that goes with regard to, if Rajon is in, who’s in what role, but I know Avery will be on the court,” Stevens said.

“I think he’s a guy that, when you look at him on both ends of the floor, he’s a guy that I think we can fit in well offensively at the point guard spot.

“I think he’s really excited about playing it. And then defensively, he can be elite.”

Bradley, who is a natural shooting guard, struggled in his role as a fill-in point guard toward the end of last season, especially in the Celtics’ first-round playoff series against the New York Knicks.

The only true point guard on the Boston roster at the moment is undrafted free agent Phil Pressey, who played at Missouri and is the son of Paul Pressey, a former Celtics assistant coach.